Auto injector with adaptable air-shot mechanism

ABSTRACT

Disclosed is an auto injector for administering a medicament. The auto injector comprising: a housing; a cartridge receiver configured to receive a cartridge assembly comprising a cartridge (700) and a cartridge code (1000) feature, the cartridge containing the medicament; a code sensor configured to read the cartridge code feature; a drive module coupled to move a plunger rod; and a processing unit coupled to the code sensor and the drive module. The processing unit being configured to: receive from the code sensor a code signal indicative of the cartridge code feature; control the drive module to move the plunger rod to a first plunger rod position, the first plunger rod position being based on the code signal; receive a trigger event; control the drive module to move the plunger rod to a second plunger rod position following reception of the trigger event.

The present disclosure relates to an auto injector, such as anelectronic auto injector, a cartridge assembly for an auto injector, asystem comprising an auto injector and a cartridge assembly, and amethod for operating an auto injector.

INTRODUCTION/BACKGROUND

Hypodermic syringes are widely used to deliver fluids to the body. It isknown to have hypodermic syringes applicable for manual operation.However, auto injectors, such as electronic auto injectors, have beendeveloped and are widely used to aid the administering of fluid ormedicaments to the body.

To avoid relying on users correctly performing certain tasks, it is ofincreasing interest that the auto injector automatically carries out asmuch as possible of the injection process.

It is generally known that air in a syringe should be depleted orminimized before injecting the medicament of the syringe. Injection ofair may potentially cause problems such as air embolism e.g. in intravenous delivery. Thus, depletion or minimization of air in the syringeis usually performed before injecting the medicament. Also, for someinjection systems minimized residual air trapped inside the syringe maypositively influence resulting dose accuracy.

Depletion or minimization of air is usually done by performing anair-shot. An air-shot is generally performed by pointing the syringeupwards, such that the air is near the opening of the syringe, andperforming an expelling action until medication is expelled. Thereby,the air is forced out of the syringe.

US 2009/299328 shows injection devices that can inject materials atpredetermined, user selected injection rates, allowing the operator morecontrol than a traditional syringe. The devices can allow mixing of morethan one substance and/or reconstitution of a solid substance forinjection.

SUMMARY

In spite of the known prior art, there is a need for an auto injector,such as an electronic auto injector, with an improved capability andaccuracy of automatically performing an air-shot. The present disclosureprovides an auto injector, a cartridge assembly, a system, and a methodimproving the capability of automatically performing an air-shot.

Accordingly, an auto injector for administering a medicament isdisclosed. The auto injector comprises: a housing, a cartridge receiver,a code sensor, a drive module, and a processing unit.

The cartridge receiver is configured to receive a cartridge assemblycomprising a cartridge and a cartridge code feature, the cartridgecontaining the medicament.

The code sensor is configured to read the cartridge code feature.

The drive module is coupled to move a plunger rod.

The processing unit is coupled to the code sensor and the drive module.The processing unit is configured to: receive from the code sensor acode signal indicative of the cartridge code feature; and control thedrive module to move the plunger rod to a first plunger rod position,the first plunger rod position being based on the code signal.

The processing unit may further be configured to receive a triggerevent, such as a trigger event after the plunger rod has been moved tothe first plunger rod position; and control the drive module to move theplunger rod to a second plunger rod position following reception of thetrigger event.

Also disclosed is a cartridge assembly for an auto injector, such as acartridge assembly for the disclosed auto injector. The cartridgeassembly comprising a cartridge and a cartridge code feature. Thecartridge containing a medicament. The cartridge code feature beingconfigured to be read by a code sensor of the auto injector for moving aplunger rod of the auto injector to a first plunger rod position basedon the cartridge code feature.

Also disclosed is a system comprising a cartridge assembly, such as thedisclosed cartridge assembly, and an auto injector, such as thedisclosed auto injector. The cartridge assembly comprises a cartridgeand a cartridge code feature, the cartridge containing a medicament. Theauto injector comprises: a housing; a cartridge receiver configured toreceive the cartridge assembly; a code sensor configured to read thecartridge code feature; a drive module coupled to move a plunger rod;and a processing unit coupled to the code sensor and the drive module.The processing unit being configured to: receive from the code sensor acode signal indicative of the cartridge code feature; and control thedrive module to move the plunger rod to a first plunger rod position,the first plunger rod position being based on the code signal.

The processing unit may further be configured to: receive a triggerevent, such as a trigger event after the plunger rod has been moved tothe first plunger rod position; and control the drive module to move theplunger rod to a second plunger rod position following reception of thetrigger event.

Also disclosed is a method for operating an auto injector comprising aplunger rod, such as the disclosed auto injector. The method comprising:receiving a cartridge assembly comprising a cartridge and a cartridgecode feature, the cartridge containing a medicament; reading thecartridge code feature; and moving the plunger rod to a first plungerrod position, the first plunger rod position being based on thecartridge code feature.

The method may further comprise: receiving a trigger event, such asreceiving a trigger event after the plunger rod has been moved to thefirst plunger rod position; and moving the plunger rod to a secondplunger rod position following reception of the trigger event.

It is an advantage of the present disclosure that the air-shot may beadapted to the specific cartridge inserted into the auto injector,thereby leading to a more precise air-shot, which may prevent or atleast reduce expelling of medicament during the air-shot.

It is an advantage of the present disclosure that the air-shot may beperformed without expelling medicament through the tip of the needle,such as a needle of the syringe and/or a needle attached to the syringe.In some situations, it may be important or desired, that dosages areknown accurately. Hence, it may be desirable that the amount ofmedicament in the syringe is fully injected into the patient and it istherefore an advantage that the air-shot may be performed automatically,and without expelling medicament through the tip of the needle.

Furthermore, medicament on the tip of a needle may provide patientdiscomfort upon insertion of the needle. And, especially for somemedicaments, it may be undesirable to spill medicament, e.g. on thefloor. It is thus a further advantage of performing the air-shot withoutexpelling medicament from the tip of the needle that patient discomfortmay be reduced.

It is a further advantage of the present disclosure that residual airtrapped in the cartridge compartment together with drug to be injectedmay be minimized.

It is thus advantageous that the present disclosure may increase dosageaccuracy, decrease patient discomfort, and/or avoid spilled medicament.

It is envisaged that any embodiments or elements as described inconnection with any one aspect may be used with any other aspects orembodiments, mutatis mutandis.

The cartridge receiver may be configured to receive the cartridge and/orcartridge assembly through a cartridge receiver opening. Thus, thecartridge and/or cartridge assembly may be inserted in the cartridgereceiver through the cartridge receiver opening.

The cartridge may comprise a cartridge compartment. The cartridgecompartment may contain the medicament.

The cartridge may comprise a cartridge outlet, e.g. at a first cartridgeend. The cartridge outlet may be configured for fluid communication withthe compartment, e.g. at the first cartridge end. The cartridge may beconfigured to expel medicament through the cartridge outlet. Thecartridge outlet may be configured to be coupled with a needle, such asa hypodermic needle, to provide the medicament to be expelled throughthe needle.

The cartridge assembly may comprise the needle, such as a needleassembly comprising the needle. The needle assembly may comprise aneedle cover and/or a needle hub. The cartridge assembly may comprise acartridge holder. The cartridge holder may be configured to engage withthe needle assembly. The cartridge holder may provide for attachment ofthe needle assembly to the cartridge.

The cartridge may comprise a first stopper movable inside the cartridgecompartment, e.g. towards the cartridge outlet, e.g. in a first stopperdirection, such as towards the first cartridge end. For example, themedicament may be expelled through the cartridge outlet upon movement ofthe first stopper, e.g. in the first stopper direction and/or towardsthe cartridge outlet.

The cartridge may comprise a cartridge back face, e.g. at a secondcartridge end, such as opposite the cartridge outlet. The cartridge backface may comprise a cartridge back end opening. The cartridge back endopening may provide access for the plunger rod to the first stopper.

The cartridge code feature may comprise one or more of a colour, a barcode, an RFID tag, an NFC tag, an identification number, and a QR code.

For example, the cartridge code feature may comprise a colour and/or asequence of colours.

The cartridge code feature may be positioned surrounding or partlysurrounding a part of the cartridge compartment wherein a stopper, suchas the first stopper, is initially positioned. Such position of thecartridge code feature may increase readability of the cartridge codefeature, e.g. since the stopper may form a background for the cartridgecode feature. The stopper, such as the first stopper may be a lightcolour, such as light grey or white. The stopper, such as the firststopper, may be a dark colour, such as dark blue, dark grey, or black.The stopper may form a dark background for the cartridge code feature.The stopper, such as the first stopper, may reduce reflection of light,e.g. to further increase readability of the cartridge code feature. Thecartridge code feature being positioned at a part of the cartridgecompartment wherein a stopper is positioned may avoid unnecessarilycovering of visible area into the cartridge compartment, e.g. forpurpose of visual inspection of the medicament.

The cartridge code feature may be positioned at a specific position onthe cartridge, e.g. independently of the stopper(s), such as the firststopper. For example, the cartridge code feature may be positioned at acode distance from the second cartridge end. All cartridges may havetheir cartridge code features positioned at the same position, e.g.positioned at the code distance from the second cartridge end. Suchuniform position of the cartridge code feature may decrease complexity,and decrease size, of the auto injector, as the cartridge code featureis read in the same position for all suitable cartridges.

The cartridge and the cartridge code feature may be manufactured as oneelement. For example, the cartridge code feature may be a certain formof the cartridge. Alternatively, the cartridge code feature may beattached to the cartridge, such as fastened, e.g. by glue, to thecartridge. For example, the cartridge code feature may be a colour codeprinted on the cartridge.

The cartridge code feature may be indicative of one or more cartridgespecifications, such as medicament in the cartridge, concentration ofmedicament in the cartridge, viscosity of medicament in the cartridge,volume and/or mass of medicament in the cartridge, positions ofstopper(s) in the cartridge compartment, etc. The cartridge code featuremay be indicative of a position of the first stopper wherein air in thecartridge compartment is reduced, such as minimized and/or reduced to anamount appropriate for injection. The cartridge code feature may beindicative of the amount of medicament contained in the cartridge. Thecartridge code feature may be indicative of a specific type ofcartridge, such as an ID number of the specific type of cartridge. Theauto injector, such as the processing unit of the auto injector, may beconfigured to determine one or more cartridge specifications based on anID number, e.g. by table lookup. The cartridge code feature may beindicative of a suitable speed of stopper movement. For example, thecartridge code feature may be indicative of the speed of movement of theplunger rod to the first plunger rod position and/or to the secondplunger rod position and/or to a third plunger rod position. Thecartridge code feature may be indicative of a suitable speed of stoppermovement, such as stopper movement in different phases of movement, suchas during air-shot and/or injection, such as towards the first plungerrod position and/or towards the second plunger rod position.

The cartridge code feature may be indicative of one or more delays, suchas time delays, e.g. comprising a delay to elapse before initiating amovement of the plunger rod and/or first stopper and/or comprising adelay to elapse between completion of one movement of the plunger rodand/or first stopper and initiation of another movement of the plungerrod and/or first stopper.

The one or more delays may comprise a first delay. The first delay maybe required to elapse before the plunger rod is moved to the firstplunger rod position. For example, the first delay may be required toelapse before initiation of movement of the plunger rod to the firstplunger rod position. For example, the first delay may be chosen toallow the medicament to settle before initiating the air-shot, e.g.after a reconstitution or mixing of the medicament, which may cause afoaming effect in the medicament. The first delay may allow the foamingeffect in the medicament to settle.

The one or more delays may comprise a second delay. The second delay maybe required to elapse before the plunger rod is moved to the secondplunger rod position. For example, the second delay may be required toelapse after completion of movement of the plunger rod to the firstplunger rod position and before initiation of movement of the plungerrod to the second plunger rod position.

The auto injector and/or the processing unit may be configured todetermine the first delay and/or the second delay based on the codesignal.

The auto injector may be an electronic auto injector. The auto injectormay comprise a battery. The housing may accommodate the battery. Thebattery may be a rechargeable battery. For example, the battery may be aLi-ion battery or a NiCd battery or a NiMH battery. The battery may beconfigured to be charged by connection of a charger.

The drive module is coupled to move, such as actuate, such as advance,the plunger rod. The drive module may comprise one or more electricalelements. The drive module may be configured to receive electrical powerfrom the battery. The drive module may be electrically connected to thebattery for receiving electrical power. The drive module may beaccommodated by the housing. The drive module may comprise a motor, suchas an electro-mechanical motor, such as a DC motor, e.g. a DC motor withor without brushes. The drive module may comprise a solenoid motor.

The drive module may comprise a shape memory metal engine. The drivemodule may comprise an arrangement of springs configured to actuate theplunger rod. The drive module may comprise a pressurized gas configuredto actuate the plunger rod.

The plunger rod may be configured to advance a first stopper, such asthe first stopper of the cartridge. The advancement of the first stoppermay be to expel medicament from the cartridge compartment through thecartridge outlet and/or to expel air from the cartridge compartmentthrough the cartridge outlet. The plunger rod may be movable between aretracted plunger rod position and an extended plunger rod position.

The auto injector, such as the processing unit of the auto injector, maybe configured to receive a trigger event, such as a trigger eventindicating that the user initiates injection of the medicament. The autoinjector, such as the processing unit of the auto injector, may beconfigured to receive the trigger event after the plunger rod has beenmoved to the first plunger rod position.

The trigger event may be used to start an injection sequence of the autoinjector. The auto injector, such as the processing unit of the autoinjector, may control the drive module to move the plunger rod to asecond plunger rod position, such as a position wherein the medicamentis injected and/or ejected from the cartridge compartment, followingreception of the trigger event. The trigger event may initiate themovement of the plunger rod to expel medicament from the cartridgecompartment through the cartridge outlet.

The trigger event may, for example, be an effect of a push of a button,an effect of an elapsed timeout, and/or an effect of a predetermineduser behaviour. The trigger event may be indicative of the auto injectorbeing pressed against the injection site.

The auto injector may comprise an ejection sensor, e.g. configured todetect the ejection, such as the expelling, of medicament and/or air inthe cartridge compartment. The ejection sensor may be configured todetect and/or determine the position of the plunger rod and/or theposition of the first stopper. The ejection sensor may be configured todetect conditions indicative of the position of the plunger rod and/orthe position of the first stopper. The ejection sensor may be configuredto provide an ejection sensor signal. The ejection sensor signal may beindicative of the position of the plunger rod and/or the first stopper.

The ejection sensor may comprise a tachometer, e.g. a tachometer of thedrive module. The tachometer may be configured to count the revolutionsof the drive module, such as a motor of the drive module, such as therevolutions of the drive module from a set point, such as a pointwherein the position of the plunger rod is known, such as a fullyretracted position of the plunger rod. The count of revolutions of thedrive module may be used to determine the actual position of the plungerrod, such as the first plunger rod position and/or the second plungerrod position.

The processing unit may be coupled to the ejection sensor, such as tothe tachometer of the ejection sensor. The processing unit may receivefrom the ejection sensor a first ejection sensor signal, such as atachometer signal, indicative of the count of revolutions of the drivemodule. The processing unit may determine the position of the plungerrod based on the first ejection sensor signal. The processing unit mayreceive a second ejection sensor signal, e.g. from the ejection sensor,indicative of the plunger rod being in a known position, such as a fullyretracted position. The processing unit may determine the position ofthe plunger rod based on the first ejection sensor signal and the secondejection sensor signal.

The ejection sensor signal may include the first ejection sensor signaland/or the second ejection sensor signal.

The first plunger rod position may be selected to expel air from thecartridge. For example, the first plunger rod position may be selectedto position the first stopper in a position wherein air in the cartridgecompartment is reduced, such as minimized and/or reduced to an amountappropriate for injection. The first plunger rod position may be aposition of the plunger rod wherein the air-shot has been completed. Thefirst plunger rod position may be a position wherein air has beenexpelled from the cartridge compartment, such as wherein the firststopper is in a position wherein air has been expelled from thecartridge compartment. The first plunger rod position may be positionedbetween the retracted plunger rod position and the extended plunger rodposition. The first plunger rod position may be based on the cartridgecode feature. For example, the processing unit may be configured todetermine the first plunger rod position based on the code signal.

The second plunger rod position may be selected to expel medicament fromthe cartridge. For example, the second plunger rod position may beselected to position the first stopper in a position wherein medicamentin the cartridge compartment is reduced, such as minimized, such as in aposition closest to the cartridge outlet. The second plunger rodposition may be positioned between the first plunger rod position andthe extended plunger rod position. The second plunger rod position maybe the extended plunger rod position. The second plunger rod positionmay be based on the cartridge code feature. For example, the processingunit may be configured to determine the second plunger rod positionbased on the code signal.

The third plunger rod position may be selected to mix a plurality ofcomponents of the medicament, e.g. to reconstitute the medicament. Forexample, the third plunger rod position may be selected to position thefirst stopper in a position wherein a first medicament component ismixed with a second medicament component. The third plunger rod positionmay be positioned between the retracted plunger rod position and thefirst plunger rod position. The third plunger rod position may be basedon the cartridge code feature. For example, the processing unit may beconfigured to determine the third plunger rod position based on the codesignal.

A fourth plunger rod position may be configured to advance the firststopper to a position before mixing of the plurality of components ofthe medicament is commenced. The fourth plunger rod position may bepositioned between the retracted plunger rod position and the thirdplunger rod position. The fourth plunger rod position may be based onthe cartridge code feature. For example, the processing unit may beconfigured to determine the fourth plunger rod position based on thecode signal.

Movements of the plunger rod may be separated and/or preceded and/orfollowed by the one or more delays.

The auto injector may comprise a user interface, such as a userinterface allowing user input and/or provide visual and/or audibleoutput to the user.

The auto injector may comprise a trigger member, such as a triggermember of the user interface. The trigger event may comprise activationof the trigger member. The trigger member may be a button of the userinterface, such as a push-button. Alternatively or additionally, thetrigger member may be a contact member, such as a skin sensor. Thecontact member may be configured to be pressed against the injectionsite for activation. For example, to activate the injection of themedicament. The contact member may be surrounding the cartridge outletand/or the intended position of the cartridge outlet, such as thecartridge receiver opening. The contact member may be configured toactivate a contact sensor when pressed against the skin, e.g. when movedrelative to the housing. The contact sensor may be configured totransmit the trigger event. The processing unit may be coupled to thecontact sensor. The processing unit may be configured to receive thetrigger event from the contact sensor.

The auto injector may comprise an orientation sensor. The orientationsensor may be configured to detect an orientation of the cartridgeand/or an orientation indicative of the orientation of the cartridge,such as an orientation of the auto injector. The orientation sensor maybe configured to detect the direction of gravity, and/or if thedirection of gravity is within a certain range of a predetermineddirection. The orientation sensor may comprise an accelerometer. Theorientation sensor may comprise a plurality of accelerometers, such asthree accelerometers, such as three accelerometers arranged to detectacceleration in three dimensions, such as a three-dimensionalaccelerometer. The orientation sensor may comprise a tilt sensor, atri-axial accelerometer, a single axis accelerometer, a magnetometerand/or any combination thereof, and the orientation sensor may provide ameasure of roll, pitch and azimuth, a measure of acceleration and/ortilt in one or more directions.

The orientation sensor may be configured to detect if the cartridge isin a predetermined orientation. The orientation sensor may be configuredto detect if the orientation of the auto injector is indicative of thecartridge being in the predetermined orientation. The predeterminedorientation may be a vertical orientation. The predetermined orientationmay be an orientation within 45 degrees of vertical, such as within 30degrees of vertical. The predetermined orientation may be an orientationwherein the cartridge is orientated such that a longitudinal axis of thecartridge is within 45 degrees of vertical, such as within 30 degrees ofvertical, and wherein the cartridge outlet is above the cartridgecompartment, such as in a vertical position above the cartridgecompartment.

The processing unit may be coupled to the orientation sensor. Theprocessing unit may be configured to receive from the orientation sensoran orientation signal indicative of the orientation of the cartridgewhen received in the cartridge receiver, and/or of the auto injector.The processing unit may be configured to control the drive module tomove the plunger rod to the first plunger rod position based on theorientation signal. For example, the processing unit may be configuredto control the drive module to move the plunger rod to the first plungerrod position only if the orientation signal indicates that a tilt anglebetween vertical and a longitudinal axis extending along the cartridgeis within 45 degrees, such as within 30 degrees, of vertical and/or ifthe cartridge outlet is in a vertical position above the cartridgecompartment.

The auto injector may comprise a code sensor, such as a code sensorconfigured to read the cartridge code feature. The code sensor may beconfigured to transmit a code signal indicative of the cartridge codefeature. The code sensor may be configured to read the cartridge codefeature in a plurality of positions. The cartridge code sensor may bemovable. The cartridge code sensor may comprise a plurality of sensors,such as a plurality of transmitters and/or receivers.

The auto injector, such as the processing unit of the auto injector, maybe configured to move the plunger rod based on the code signal and/orthe cartridge code feature. The auto injector, such as the processingunit of the auto injector, may be configured to move the plunger rod tothe first plunger rod position based on the code signal and/or thecartridge code feature. The first plunger rod position, e.g. wherein theair-shot is completed, may be determined based on the cartridgeassembly, such as on the cartridge code feature, such as on thecartridge code signal. The movement of the plunger rod and/or the firststopper may be based on the cartridge assembly, e.g. on the cartridgecode feature. Thus, the air-shot may be performed with reduced or noexpelling of medicament, thereby increasing dosage accuracy and/orreduce patient discomfort.

Movement of the plunger rod may comprise movement having a plunger rodspeed, such as a first plunger rod speed and/or a second plunger rodspeed. The plunger rod speed may be based on the position of the plungerrod. The plunger rod may be moved to the first plunger rod position witha first plunger rod speed. The plunger rod may be moved to the secondplunger rod position, such as from the first plunger rod position, witha second plunger rod speed. The second plunger rod speed may be fasteror slower than the first plunger rod speed.

The plunger rod may be moved to the third plunger rod position with athird plunger rod speed. The plunger rod may be moved to the fourthplunger rod position with a fourth plunger rod speed.

The first plunger rod speed and/or the second plunger rod speed and/orthe third plunger rod speed and/or the fourth plunger rod speed may bebased on a cartridge specification, such as on the cartridge codefeature, such as on the code signal. The processing unit may beconfigured to determine the first plunger rod speed and/or the secondplunger rod speed and/or the third plunger rod speed and/or the fourthplunger rod speed, based on the code signal.

The processing unit may be configured to control the drive module tomove the plunger rod to the first plunger rod position with the firstplunger rod speed. The processing unit may be configured to control thedrive module to move the plunger rod to the second plunger rod position,such as from the first plunger rod position, with the second plunger rodspeed.

The code sensor may comprise an optical sensor. The code sensor maycomprise an optical sensor comprising a transmitter and a receiver, suchas a light transmitter and a light receiver. The code sensor may beconfigured to read the cartridge code feature. The code sensor may beconfigured to read QR codes, bar codes, colour codes, and/or anycombination hereof.

The auto injector may comprise a temperature sensor. The temperaturesensor may be configured to provide a temperature signal, such as atemperature signal indicative of the temperature of the auto injectorand/or of the cartridge and/or of the medicament. The temperature sensormay comprise an infrared sensor, such as an optical infrared sensor. Thetemperature sensor and the code sensor may be the same sensor. Forexample, an optical infrared sensor for sensing temperature may be thesame physical sensor as an optical sensor for reading the cartridge codefeature.

The processing unit may be coupled to the temperature sensor. Theprocessing unit may be configured to receive the temperature signal.

Movement of the plunger rod, e.g. to the first plunger rod positionand/or to the second plunger position, may be based on the temperatureof the auto injector and/or of the cartridge and/or of the medicament,e.g. on the temperature signal.

The auto injector, such as the processing unit, may be configured tocontrol the drive module based on the temperature signal. For example,the processing unit may be configured to control the drive module tomove the plunger rod to the first plunger rod position and/or to thesecond plunger rod position based on the temperature signal.

The first plunger rod speed and/or the second plunger rod speed and/orthe third plunger rod speed and/or the fourth plunger rod speed may bedetermined based on temperature, such as the temperature of the autoinjector and/or of the cartridge and/or of the medicament, e.g. on thetemperature signal. The first plunger rod position and/or the secondplunger rod position and/or the third plunger rod position and/or thefourth plunger rod position may be determined based on the temperaturesignal and/or temperature, such as the temperature of the auto injectorand/or of the cartridge and/or of the medicament. For example, thevolume of the medicament may be dependent on temperature, and therefore,the air-shot may be more precisely controlled when taking into accountthe temperature. Thus, the air-shot may be performed with reduced or noexpelling of medicament, thereby, for example, increasing dosageaccuracy and/or reducing patient discomfort.

The processing unit may be coupled to the orientation sensor, the codesensor, the ejection sensor, and/or the temperature sensor. Theprocessing unit may be configured to receive the orientation signal, thecode signal, the ejection sensor signal, and/or the temperature signal.The processing unit may be configured to control the drive module tomove the plunger rod to the first plunger rod position and/or the secondplunger rod position based on the orientation signal, the code signal,the ejection sensor signal, and/or the temperature signal.

The auto injector may comprise a cartridge sensor. The cartridge sensormay be configured to detect reception of a cartridge assembly in theauto injector and/or in the cartridge receiver of the auto injector. Thecartridge sensor may provide a cartridge sensor signal indicative ofreception of a cartridge assembly. The code sensor and the cartridgesensor may be the same sensor, e.g. the code sensor may be configured todetect reception of a cartridge assembly and subsequently read thecartridge code feature.

The processing unit may be coupled to the cartridge sensor. Theprocessing unit may be configured to receive the cartridge sensorsignal. The processing unit may be configured to control the drivemodule based on the cartridge sensor signal. For example, the processingunit may be configured to control the drive module to start movement ofthe plunger rod if a cartridge assembly is received, and/or only if acartridge assembly is received.

The auto injector may comprise a needle sensor. The needle sensor may beconfigured to detect a needle, and/or a needle assembly, and/or a needlecover of a needle assembly, of the cartridge assembly, e.g. when thecartridge assembly is received in the auto injector and/or in thecartridge receiver of the auto injector. The needle sensor may provide aneedle signal indicative of the presence of a needle, and/or a needleassembly, and/or a needle cover of a needle assembly.

The processing unit may be coupled to the needle sensor. The processingunit may be configured to receive the needle signal. The processing unitmay be configured to control the drive module based on the needlesignal. For example, the processing unit may be configured to controlthe drive module to start movement of the plunger rod only if a needleis present, and/or only if a needle cover is not present.

The auto injector may comprise a resistance sensor. The resistancesensor may be configured to detect resistance against movement of theplunger rod. The resistance sensor may be configured to detectresistance against movement of the plunger rod based on measurements ofthe drive module. For example, the resistance sensor may be configuredto detect the electrical current of a motor of the drive module. Theresistance sensor may be configured to provide a resistance signalindicative of resistance against movement of the plunger rod.

The processing unit may be coupled to the resistance sensor. Theprocessing unit may be configured to receive the resistance signal. Theprocessing unit may be configured to determine the resistance againstmovement of the plunger rod based on the resistance signal. Theprocessing unit may be configured to control the drive module based onthe resistance signal. For example, the processing unit may beconfigured to control the drive module to adjust movement of the plungerrod based on the resistance signal. For example, the processing unit maybe configured to control the drive module to start, stop or continuemovement of the plunger rod based on the resistance signal.

BRIEF DESCRIPTION OF THE FIGURES

A more detailed description follows below with reference to the drawing,in which:

FIG. 1 illustrates an exemplary auto injector;

FIG. 2 illustrates an exemplary auto injector with a cartridge;

FIG. 3 schematically illustrates an exemplary cartridge;

FIGS. 4a-d schematically illustrates an exemplary cartridge withexemplary cartridge code features;

FIG. 5 schematically illustrates an exemplary auto injector with acartridge;

FIG. 6a-c schematically illustrates an exemplary cartridge and a plungerrod in exemplary positions;

FIG. 7 shows a block diagram of an exemplary auto injector; and

FIG. 8 shows a flow chart of an exemplary method.

DETAILED DESCRIPTION

Various embodiments are described hereinafter with reference to thefigures. Like reference numerals refer to like elements throughout. Likeelements will, thus, not be described in detail with respect to thedescription of each figure. It should also be noted that the figures areonly intended to facilitate the description of the embodiments. They arenot intended as an exhaustive description of the claimed invention or asa limitation on the scope of the claimed invention. In addition, anillustrated embodiment needs not have all the aspects or advantagesshown. An aspect or an advantage described in conjunction with aparticular embodiment is not necessarily limited to that embodiment andcan be practiced in any other embodiments even if not so illustrated, orif not so explicitly described.

FIG. 1 illustrates an exemplary auto injector 4. The auto injector 4 maybe configured for administering a medicament. The auto injector 4 may bean electronic auto injector.

The auto injector 4 comprises a housing 6. The auto injector 4 comprisesa cartridge receiver 300. The cartridge receiver is configured toreceive a cartridge and/or a cartridge assembly comprising a cartridge.The cartridge may contain the medicament.

The cartridge receiver 300 has a cartridge receiver opening 301. Thecartridge receiver 300 is configured to receive the cartridge and/or thecartridge assembly through the cartridge receiver opening 301 in acartridge receiving direction 304 along a longitudinal axis L.

The auto injector 4 may comprise a user interface 1100, as illustrated.The auto injector 4 comprises a trigger member, such as the contactmember 1102. The contact member 1102 may be configured to be pressedagainst an injection site. The contact member 1102 may be movable in thecartridge receiving direction 304, relative to the housing 6, if pressedagainst the injection site. The contact member 1102 may be part of theuser interface 1100.

FIG. 2 illustrates an exemplary system 2. The system 2 comprises an autoinjector 4, as described in relation to FIG. 1, and an exemplarycartridge 700 received in the cartridge receiver 300. The cartridge 700is shown with a needle cover 908. The needle cover 908 extending out ofthe contact member 1102 to allow removal of the needle cover 908 fromthe cartridge 700.

FIG. 3 schematically illustrates an exemplary cartridge 700, such as acartridge 700 being configured to be received in the cartridge receiverof an auto injector, such as the auto injector described in relation toprevious figures.

The cartridge 700 comprises a cartridge compartment 702. The cartridgecompartment 702 may be configured for containing a medicament. Thecartridge 700 has a first end 718 and a second end 720. The cartridge700 comprises a cartridge outlet 714 at the first cartridge end 718. Thecartridge 700 may be configured to expel medicament through thecartridge outlet 714.

The cartridge 700 comprises a first stopper 708 movable inside thecartridge compartment 702, e.g. in a first stopper direction 722, e.g.towards the first cartridge end 718. For example, the medicament may beexpelled through the cartridge outlet 714 upon movement of the firststopper 708 in the first stopper direction 722. The cartridge comprisesa cartridge back face 716 at the second cartridge end 720. The cartridgeback face 716 comprises a cartridge back end opening for providingaccess to the first stopper 708 for a plunger rod.

As illustrated, the cartridge 700 may be a dual chamber cartridge. Thecartridge comprises a second stopper 710 movable inside the cartridgecompartment 702, e.g. in the first stopper direction 722, e.g. towardsthe first cartridge end 718. The cartridge compartment 702 comprises afirst cartridge subcompartment 704 and a second cartridge subcompartment706. The first cartridge subcompartment 704 is between the first stopper708 and the second stopper 710. The second cartridge subcompartment 706is between the second stopper 710 and the cartridge outlet 714. Thecartridge comprises a bypass section 712 for providing fluidcommunication between the first cartridge subcompartment 704 and thesecond cartridge subcompartment 706. The bypass section 712 providesfluid communication between the first cartridge subcompartment 704 andthe second cartridge subcompartment 706 when the second stopper 710 ispositioned in the bypass section 712.

FIGS. 4a-d schematically illustrates an exemplary cartridge assembly600. The cartridge assembly 600 comprises an exemplary cartridge 700 andan exemplary cartridge code feature 1000. The cartridge 700 has a firstcartridge end 718 and a second cartridge end 720. The first stopperdirection 722 is from the second cartridge end 720 to the firstcartridge end 718. The cartridge code feature 1000 is positioned nearthe second cartridge end 720, e.g. closer to the second cartridge end720 than the first cartridge end 718. In another exemplary cartridgeassembly, the cartridge code feature 1000 may be positioned near thefirst cartridge end 718.

FIGS. 4a-d illustrates different types of exemplary cartridge codefeatures 1000.

FIG. 4a illustrates an exemplary cartridge assembly 600, wherein thecartridge code feature 1000 comprises two strips. The two strips may becoloured, e.g. differently coloured. The combination and/or sequence ofcolours may be indicative of a code of the cartridge code feature 1000.

FIG. 4b illustrates an exemplary cartridge assembly 600, wherein thecartridge code feature 1000 comprises bar codes. The cartridge codefeature 1000 may comprise one or more bar codes. The bar code may beindicative of a number indicative of a code of the cartridge codefeature 1000.

FIG. 4c illustrates an exemplary cartridge assembly 600, wherein thecartridge code feature 1000 comprises differently grated strips. Forexample, as illustrated, the cartridge code feature 1000 may comprisetwo strips wherein the first strip is grated at 45 deg., and the secondstrip is grated at −45 deg. The grating, and/or the grating of thestrips relative to each other, may be indicative of a code of thecartridge code feature 1000.

FIG. 4d illustrates an exemplary cartridge assembly 600, wherein thecartridge code feature 1000 comprises an electromagnetically readabletag, such as an RFID tag or an NFC tag. The electromagnetically readabletag may contain data that is indicative of a code of the cartridge codefeature 1000.

FIG. 5 illustrates an exemplary system 2. The system 2 comprises an autoinjector 4, as described, for example, in relation to FIG. 1, and anexemplary cartridge assembly 600. The cartridge assembly 600 comprises acartridge 700 with a cartridge compartment 702, a needle assembly 900,and a cartridge code feature 1000. The cartridge assembly 600 isreceived in the auto injector 4.

The cartridge assembly 600 comprises a cartridge holder 800. Thecartridge holder 800 is configured for retention of the cartridge 700 inthe cartridge receiver 300 of the auto injector 4. The cartridge holder800 comprises a cartridge retention member 808. The cartridge retentionmember 808 engages with the cartridge receiver 300 for reception of thecartridge 700 and the cartridge assembly 600 in the cartridge receiver300.

The needle assembly 900 comprises a needle 902 and a needle hub 904. Theneedle assembly 900 is attached to the cartridge 700, e.g. by the needlehub 904 having a cartridge holder coupling portion 906, e.g. a threadedcoupling portion, being in engagement with a needle assembly couplingportion 812 of the cartridge holder 800. The needle 902 extends throughthe cartridge outlet 714 of the cartridge 700. The cartridge outlet 714may be blocked by a resilient sealing being penetrated by the needle902, when the needle assembly 900 is attached to the cartridge 700.

The auto injector 4 comprises a code sensor 24 configured to read thecartridge code feature 1000. When the cartridge assembly 600 isinserted, as shown, the cartridge code feature 1000 is lined up with thecode sensor 24.

The auto injector 4 comprises a plunger rod 400. The plunger rod 400 isconfigured to advance a first stopper of the cartridge 700. The plungerrod 400 comprises an outer plunger rod 404 with an inner thread, and aninner plunger rod 402 with an outer thread. The thread of the innerplunger rod 402 is in engagement with the thread of the outer plungerrod 404. The outer plunger rod 404 is prevented from rotating relativeto the housing of the auto injector. The movement of the plunger rod 400comprises rotation of the inner plunger rod 402. The rotation of theinner plunger rod 402 results in translational movement of the outerplunger rod 404, due to the outer plunger rod 404 being rotationallyrestricted. The outer plunger rod 404, when moved translationally in thefirst stopper direction 722, is configured to abut the first stopper ofthe cartridge 700, and to move the first stopper in the first stopperdirection 722.

The drive module 500 is coupled to actuate the plunger rod 400. Thedrive module 500 is electrically connected to a battery for receivingelectrical power. The drive module 500 comprises a motor 502, such as anelectro-mechanical motor, such as a DC motor. The drive module 500comprises a transmission 504 for coupling the motor 502 to the innerplunger rod 402 of the plunger rod 400

Although the example shown comprises a motor 502, which may be anelectro-mechanical motor, it will be readily understood that the autoinjector 4 may be realised having an alternative drive module, such ascomprising a solenoid motor, a shape memory metal engine, an arrangementof springs and/or a pressurized gas configured to actuate the plungerrod 400.

The auto injector 4 comprises an ejection sensor 26, such as a plungerrod position sensor. The ejection sensor 26 is configured to detect theposition of the plunger rod 400. In the illustrated example, theejection sensor 26 comprises a tachometer configured to count/detect therevolutions of the motor 502. Thus, the position of the plunger rod 400may be determined. The ejection sensor 26 may, based on the detection ofthe position of the plunger rod 400, detect the expelling of medicamentand/or air in the cartridge compartment. The position of the plunger rod400 is indicative of the position of the first stopper of the cartridge700.

FIGS. 6a-c schematically illustrates an exemplary cartridge assembly 600and a plunger rod 400 in exemplary positions.

The cartridge assembly 600 comprises a cartridge 700, a cartridge holder800, and a needle assembly 900.

The cartridge 700 comprises a cartridge compartment 702, a first stopper708 and a cartridge outlet 714. The cartridge compartment 702 isconfigured for containing a medicament (not shown). The cartridge 700shown in FIGS. 6a-c is a single chamber cartridge. However, it may be adual chamber cartridge as, for example, explained in relation to FIG. 3.

The cartridge holder 800 comprises a cartridge retention member 808. Thecartridge retention member 808 is configured for engagement with acartridge receiver of the auto injector. The cartridge holder 800comprises a needle assembly coupling portion 812. The needle assemblycoupling portion 812 is configured for engagement with a cartridgeholder coupling portion 906 of the needle assembly 900. The needleassembly coupling portion 812 allows attachment of a needle to thecartridge 700.

The needle assembly 900 comprises a needle 902 and a needle hub 904. Theneedle assembly 900 is attached to the cartridge 700, e.g. by the needlehub 904 having a cartridge holder coupling portion 906, e.g. a threadedcoupling portion, being in engagement with a needle assembly couplingportion 812 of the cartridge holder 800. The needle 902 extends throughthe cartridge outlet 714 of the cartridge 700.

FIG. 6a shows the first stopper 708 in an exemplary initial stopperposition, and the plunger rod 400 in an exemplary initial plunger rodposition. The plunger rod 400 is moved towards the cartridge outlet 714,e.g. in the first stopper direction 722, such that a plunger rod frontend 410 of the plunger rod 400 abuts the first stopper 708.

FIG. 6b shows the first stopper 708 in an exemplary first stopperposition, and the plunger rod 400 in an exemplary first plunger rodposition. Compared to FIG. 6a , the plunger rod 400 has moved towardsthe cartridge outlet 714, e.g. in the first stopper direction 722, tothe first plunger rod position. The first stopper 708 has moved to thefirst stopper position by the movement of the plunger rod 400. The firststopper 708 has been pushed by the plunger rod front end 410 of theplunger rod 400.

The first stopper position and/or the first plunger rod position mayhave been determined by a cartridge code feature (see FIG. 4), of thecartridge assembly 600.

The first stopper position and/or the first plunger rod position may bethe position of the first stopper 708 and/or the plunger rod 400 aftercompletion of an air-shot. Thus, the first stopper position and/or thefirst plunger rod position may be the position of the first stopper 708and/or the plunger rod 400 wherein air in the cartridge compartment 702has been expelled, e.g. through the cartridge outlet 714 and/or theneedle 902.

FIG. 6c shows the first stopper 708 in an exemplary second stopperposition, and the plunger rod 400 in an exemplary second plunger rodposition. Compared to FIG. 6b , the plunger rod 400 has moved towardsthe cartridge outlet 714, e.g. in the first stopper direction 722, tothe second plunger rod position. The first stopper 708 has moved to thesecond stopper position by the movement of the plunger rod 400. Thefirst stopper 708 has been pushed by the plunger rod front end 410 ofthe plunger rod 400.

The second stopper position and/or the second plunger rod position maybe the position of the first stopper 708 and/or the plunger rod 400after completion of ejection of medicament, such as after completion ofinjection of medicament. Thus, the second stopper position and/or thesecond plunger rod position may be the position of the first stopper 708and/or the plunger rod 400 wherein medicament in the cartridgecompartment 702 has been expelled, e.g. through the cartridge outlet 714and/or the needle 902.

FIG. 7 shows a block diagram of an exemplary auto injector 4. The autoinjector comprises a plurality of sensors 22, 24, 26, 28, 30, 32, 34, aprocessing unit 20, a drive module 500, and a trigger member 1102. Thesensors 22, 24, 26, 28, 30, 32, 34 are coupled to the processing unit20. The trigger member 1102 is coupled to the processing unit 20. Theprocessing unit is coupled to the drive module 500.

The processing unit 20 receives signals from the sensors 22, 24, 26, 28,30, 32, 34 and the trigger member 1102. The processing unit 20 isconfigured to control the drive module 500. The processing unit 20 maycontrol the drive module 500 based on one or more of the receivedsignals from the sensors 22, 24, 26, 28, 30, 32, 34.

The auto injector 4 comprises an orientation sensor 22. The orientationsensor 22 is configured to provide an orientation signal indicative ofthe orientation of a cartridge received in the auto injector 4. Forexample, the orientation sensor 22 may be configured to detect theorientation of the auto injector 4. The orientation of the cartridge maybe determined based on the orientation of the auto injector 4. Theorientation sensor 22 may be configured to detect the direction ofgravity. For example, the orientation sensor 22 may comprise anaccelerometer.

The processing unit 20 is coupled to the orientation sensor 22. Theprocessing unit 20 is configured to receive the orientation signal. Theprocessing unit 20 may determine the orientation of the cartridge basedon the orientation signal. The processing unit 20 may control the drivemodule 500 based on the orientation signal. For example, the processingunit 20 may be configured to control the drive module 500 to move theplunger rod to the first plunger rod position based on the orientationsignal. For example, the processing unit 20 may be configured to controlthe drive module 500 to move the plunger rod to the first plunger rodposition only if the cartridge outlet is pointing upwards, e.g. suchthat air is expelled from the cartridge compartment upon movement of theplunger rod to the first plunger rod position.

The auto injector 4 comprises a code sensor 24. The code sensor 24 isconfigured to read a cartridge code feature, and provide a code signalindicative of the cartridge code feature. For example, the code sensormay be configured to read/detect a colour code.

The processing unit 20 is coupled to the code sensor 24. The processingunit 20 is configured to receive the code signal. The processing unit 20may determine the cartridge code feature of the cartridge assembly basedon the code signal. The processing unit 20 may control the drive module500 based on the code signal. For example, the processing unit 20 may beconfigured to control the drive module 500 to move the plunger rod tothe first plunger rod position and/or the second plunger rod positionbased on the code signal. For example, the processing unit 20 may beconfigured to determine the position of the first plunger rod positionbased on the code signal.

The auto injector 4 comprises an ejection sensor 26, such as a plungerrod position sensor. The ejection sensor 26 is configured to detect theposition of the plunger rod of the auto injector 4 and/or the positionof the first stopper of the cartridge, and provide an ejection sensorsignal indicative of the position of the plunger rod and/or firststopper.

The processing unit 20 is coupled to the ejection sensor 26. Theprocessing unit 20 is configured to receive the ejection sensor signal.The processing unit 20 may determine the position of the plunger rodbased on the ejection sensor signal. The processing unit 20 may controlthe drive module 500 based on the ejection sensor signal. For example,the processing unit 20 may be configured to control the drive module 500to start, stop or continue movement of the plunger rod based on theejection sensor signal. For example, the processing unit 20 may beconfigured to determine that the plunger rod is moved to the firstplunger rod position based on the ejection sensor signal.

The auto injector 4 comprises a cartridge sensor 28. The cartridgesensor 28 is configured to detect reception of a cartridge assembly inthe auto injector 4. The cartridge sensor 28 provides a cartridge sensorsignal indicative of reception of a cartridge assembly.

The processing unit 20 is coupled to the cartridge sensor 28. Theprocessing unit 20 is configured to receive the cartridge sensor signal.The processing unit 20 may control the drive module 500 based on thecartridge sensor signal. For example, the processing unit 20 may beconfigured to control the drive module 500 to start movement of theplunger rod if a cartridge assembly is received, and/or only if acartridge assembly is received.

The code sensor 24 and the cartridge sensor 28 may be the same sensor,e.g. the code sensor 24 may be configured to detect reception of acartridge assembly and subsequently read the cartridge code feature.

The auto injector 4 comprises a needle sensor 30. The needle sensor 30is configured to detect a needle, and/or a needle assembly, and/or aneedle cover of a needle assembly, of the cartridge assembly, when thecartridge assembly is received in the auto injector 4. The needle sensor30 provides a needle signal indicative of the presence of a needle,and/or a needle assembly, and/or a needle cover of a needle assembly, ofthe cartridge assembly.

The processing unit 20 is coupled to the needle sensor 30. Theprocessing unit 20 is configured to receive the needle signal. Theprocessing unit 20 may control the drive module 500 based on the needlesignal. For example, the processing unit 20 may be configured to controlthe drive module 500 to start movement of the plunger rod only if aneedle is present, and/or only if a needle cover is not present.

The auto injector 4 comprises a temperature sensor 32. The temperaturesensor 32 is configured to detect a temperature, such as a temperatureof the auto injector and/or of the cartridge and/or of the medicament.The temperature sensor 32 is configured to provide a temperature signalindicative of the temperature.

The processing unit 20 is coupled to the temperature sensor 32. Theprocessing unit 20 is configured to receive the temperature signal. Theprocessing unit 20 may be configured to determine the temperature, suchas the temperature of the auto injector and/or of the cartridge and/orof the medicament based on the temperature signal. The processing unit20 may control the drive module 500 based on the temperature signal. Forexample, the processing unit 20 may be configured to control the drivemodule 500 to move the plunger rod to the first plunger rod positionand/or the second plunger rod position based on the temperature signal.For example, the processing unit 20 may be configured to determine theposition of the first plunger rod position based on the temperaturesignal.

The auto injector 4 comprises a resistance sensor 34. The resistancesensor 34 is configured to detect resistance against movement of theplunger rod of the auto injector 4. The resistance sensor 34 may beconfigured to detect resistance against movement of the plunger rodbased on measurements of the drive module 500. For example, theresistance sensor 34 may be configured to detect the electrical currentof a motor of the drive module 500. The resistance sensor 34 isconfigured to provide a resistance signal indicative of resistanceagainst movement of the plunger rod.

The processing unit 20 is coupled to the resistance sensor 34. Theprocessing unit 20 is configured to receive the resistance signal. Theprocessing unit 20 may be configured to determine the resistance againstmovement of the plunger rod based on the resistance signal. Theprocessing unit 20 may control the drive module 500 based on theresistance signal. For example, the processing unit 20 may be configuredto control the drive module 500 to adjust movement of the plunger basedon the resistance signal. For example, the processing unit 20 may beconfigured to control the drive module 500 to start, stop or continuemovement of the plunger rod based on the resistance signal.

The auto injector 4 is illustrated comprising all of the above mentionedsensors. However, alternatively, the auto injector may comprise only oneor any combination of one or more of the above mentioned sensors.

The auto injector comprises a trigger member 1102. The trigger member1102 is configured to provide a trigger event upon activation. Forexample, the trigger member 1102 may be a contact member configured tobe pressed against the injection site for activation.

The processing unit 20 is coupled to the trigger member 1102. Theprocessing unit 20 is configured to receive the trigger event. Theprocessing unit 20 may control the drive module 500 based on the triggerevent. For example, the processing unit 20 may be configured to controlthe drive module 500 to move the plunger rod to the second plunger rodposition following reception of the trigger event. The processing unit20 may be configured to control the drive module 500 to move the plungerrod to the second plunger rod position, e.g. to inject the medicament,only after receiving the trigger event from the trigger member 1102.

The auto injector comprises a housing 6 accommodating the sensors 22,24, 26, 28, 30, 32, 34, processing unit 20, trigger member 1102 anddrive module 500.

FIG. 8 shows a flow chart of an exemplary method 2000 for operating anauto injector, such as the auto injector as described in relation to theprevious figures. The method 2000 comprises receiving 2001 a cartridgeassembly; reading 2002 a cartridge code feature of the cartridgeassembly; moving 2004 a plunger rod of the auto injector to a firstplunger rod position, wherein the first plunger rod position is based onthe cartridge code feature; receiving a trigger event 2006; and moving2008 the plunger rod to a second plunger rod position followingreception of the trigger event.

The method 2000 furthermore comprises an optional step of determining2010 an orientation of the cartridge. This step may be performedsimultaneously with reading 2002 the cartridge code feature. However,alternatively the determining 2010 of the orientation may be performedbefore or after the reading 2002 of the cartridge code feature. Ifdetermining 2010 the orientation, movement 2004 of the plunger rod tothe first plunger rod position may be based on the determinedorientation. For example, the movement 2004 may require that thedetermined orientation is within a predefined range, e.g. of vertical.

The method 2000 furthermore comprises an optional step of detecting 2012a temperature. This step may be performed simultaneously with reading2002 the cartridge code feature and/or determining 2010 the orientation.However, alternatively the detecting 2012 of the temperature may beperformed before or after the reading 2002 of the cartridge code featureand/or before or after the determining 2010 of the orientation. Ifdetecting 2012 the temperature, the first plunger rod position mayfurther be based on the detected temperature. Movement 2008 of theplunger rod to the second plunger rod position may be based on thedetected temperature. For example, the speed of the movement 2008 may bebased on the detected temperature.

Steps of the exemplary method 2000, especially the steps of reading 2002a cartridge code feature of the cartridge assembly; optionallydetermining 2010 an orientation of the cartridge; optionally detecting2012 a temperature;

moving 2004 a plunger rod of the auto injector to a first plunger rodposition; receiving a trigger event 2006; and moving 2008 the plungerrod to a second plunger rod position, may be controlled by a processingunit, such as the processing unit of the auto injector.

Exemplary auto injectors, cartridges, systems and methods are set out inthe following items:

1. An auto injector for administering a medicament, comprising:

-   -   a housing;    -   a cartridge receiver configured to receive a cartridge assembly        comprising a cartridge and a cartridge code feature, the        cartridge containing the medicament;    -   a code sensor configured to read the cartridge code feature;    -   a drive module coupled to move a plunger rod; and    -   a processing unit coupled to the code sensor and the drive        module;

the processing unit being configured to:

-   -   receive from the code sensor a code signal indicative of the        cartridge code feature; and    -   control the drive module to move the plunger rod to a first        plunger rod position, the first plunger rod position being based        on the code signal.

2. Auto injector according to item 1, wherein the first plunger rodposition is selected to expel air from the cartridge.

3. Auto injector according to any of items 1 or 2, wherein theprocessing unit is further configured to:

-   -   receive a trigger event; and    -   control the drive module to move the plunger rod to a second        plunger rod position following reception of the trigger event.

4. Auto injector according to item 3 comprises a trigger member, andwherein the trigger event comprises activation of the trigger member.

5. Auto injector according any of items 3 or 4, wherein the triggerevent is indicative of the auto injector being pressed against theinjection site.

6. Auto injector according to any of the preceding items comprising anorientation sensor, wherein the processing unit is coupled to theorientation sensor, the processing unit being configured to receive fromthe orientation sensor an orientation signal indicative of theorientation of the cartridge when received in the cartridge receiver,and the processing unit being configured to control the drive module tomove the plunger rod to the first plunger rod position based on theorientation signal.

7. Auto injector according to item 6, wherein the orientation sensorcomprises an accelerometer.

8. Auto injector according to any of items 6 or 7, the processing unitbeing configured to control the drive module to move the plunger rod tothe first plunger rod position if the orientation signal indicates thata tilt between vertical and a longitudinal axis extending along thecartridge is within 45 degrees of vertical and a cartridge outlet of thecartridge is in a vertical position above a cartridge compartment of thecartridge, the cartridge compartment containing the medicament.

9. Auto injector according to any of the preceding items, wherein thecode sensor comprises an optical sensor.

10. Auto injector according to any of the preceding items, wherein thecartridge code feature comprises one or more of a colour, a bar code, anRFID tag, an NFC tag, an identification number, and a QR code.

11. Auto injector according to any of the preceding items comprising atemperature sensor configured to provide a temperature signal indicativeof the temperature of the cartridge when received in the cartridgereceiver, wherein the processing unit is coupled to the temperaturesensor and configured to receive the temperature signal, and theprocessing unit being configured to control the drive module to move theplunger rod to the first plunger rod position based on the temperaturesignal.

12. Auto injector according to any of the preceding items, wherein theplunger rod is moved to the first plunger rod position with a firstplunger rod speed based on the code signal.

13. A cartridge assembly for an auto injector comprising a cartridge anda cartridge code feature, the cartridge containing a medicament, thecartridge code feature being configured to be read by a code sensor ofthe auto injector for moving a plunger rod of the auto injector to afirst plunger rod position based on the cartridge code feature.

14. Cartridge assembly according to item 13, wherein the cartridgecomprises a cartridge compartment containing the medicament, a cartridgeoutlet, and a first stopper movable inside the cartridge compartmenttowards the cartridge outlet, wherein the cartridge code feature isindicative of a position of the first stopper wherein air in thecartridge compartment is reduced.

15. Cartridge assembly according to any of items 13 or 14, wherein thecartridge compartment has a first cartridge subcompartment containing afirst medicament component of the medicament and a second cartridgesubcompartment containing a second medicament component of themedicament, wherein the first medicament component is a fluid and thesecond medicament component is a lyophilized medicament.

16. A system comprising a cartridge assembly and an auto injector, thecartridge assembly comprising a cartridge and a cartridge code feature,the cartridge containing a medicament, the auto injector comprising:

-   -   a housing;    -   a cartridge receiver configured to receive the cartridge        assembly;    -   a code sensor configured to read the cartridge code feature;    -   a drive module coupled to move a plunger rod; and    -   a processing unit coupled to the code sensor and the drive        module;

the processing unit being configured to:

-   -   receive from the code sensor a code signal indicative of the        cartridge code feature; and    -   control the drive module to move the plunger rod to a first        plunger rod position, the first plunger rod position being based        on the code signal.

17. System according to item 16, wherein the processing unit is furtherconfigured to:

-   -   receive a trigger event; and    -   control the drive module to move the plunger rod to a second        plunger rod position following reception of the trigger event.

18. A method for operating an auto injector comprising a plunger rod,the method comprising:

-   -   receiving a cartridge assembly comprising a cartridge and a        cartridge code feature, the cartridge containing a medicament;    -   reading the cartridge code feature; and    -   moving the plunger rod to a first plunger rod position, the        first plunger rod position being based on the cartridge code        feature.

19. Method according to item 18 further comprising:

-   -   receiving a trigger event;    -   moving the plunger rod to a second plunger rod position        following reception of the trigger event.

20. Method according to any of items 18 or 19, wherein the plunger rodis moved to the first plunger rod position with a first plunger rodspeed based on the code signal.

1. An auto injector for administering a medicament, comprising: ahousing; a cartridge receiver configured to receive a cartridge assemblycomprising a cartridge and a cartridge code feature, the cartridgecontaining the medicament; a code sensor configured to read thecartridge code feature; a drive module coupled to move a plunger rod;and a processing unit coupled to the code sensor and the drive module;wherein the processing unit is configured to: receive from the codesensor a code signal indicative of the cartridge code feature; andcontrol the drive module to move the plunger rod to a first plunger rodposition, the first plunger rod position being based on the code signal,and the first plunger rod position being selected to expel air from thecartridge. 2-19. (canceled)
 20. The auto injector according to claim 1,wherein the processing unit is further configured to: receive a triggerevent; and control the drive module to move the plunger rod to a secondplunger rod position following reception of the trigger event.
 21. Theauto injector according to claim 20, further comprising a triggermember, and wherein the trigger event comprises activation of thetrigger member.
 22. The auto injector according to claim 20, wherein thetrigger event is indicative of the auto injector being pressed againstthe injection site.
 23. The auto injector according to claim 1,comprising an orientation sensor, wherein the processing unit is coupledto the orientation sensor, the processing unit being configured toreceive from the orientation sensor an orientation signal indicative ofthe orientation of the cartridge when received in the cartridgereceiver, and the processing unit being configured to control the drivemodule to move the plunger rod to the first plunger rod position basedon the orientation signal.
 24. The auto injector according to claim 23,wherein the orientation sensor comprises an accelerometer.
 25. The autoinjector according to claim 23, the processing unit being configured tocontrol the drive module to move the plunger rod to the first plungerrod position if the orientation signal indicates that a tilt betweenvertical and a longitudinal axis extending along the cartridge is within45 degrees of vertical and a cartridge outlet of the cartridge is in avertical position above a cartridge compartment of the cartridge, thecartridge compartment containing the medicament.
 26. The auto injectoraccording to claim 1, wherein the code sensor comprises an opticalsensor.
 27. The auto injector according to claim 1, wherein thecartridge code feature comprises one or more of a colour, a bar code, anRFID tag, an NFC tag, an identification number, or a QR code.
 28. Theauto injector according to claim 1, further comprising a temperaturesensor configured to provide a temperature signal indicative of thetemperature of the cartridge when received in the cartridge receiver,wherein the processing unit is coupled to the temperature sensor andconfigured to receive the temperature signal, and the processing unitbeing configured to control the drive module to move the plunger rod tothe first plunger rod position based on the temperature signal.
 29. Theauto injector according to claim 1, wherein the plunger rod is moved tothe first plunger rod position with a first plunger rod speed based onthe code signal.
 30. A cartridge assembly for an auto injectorcomprising a cartridge and a cartridge code feature, the cartridgecontaining a medicament, the cartridge code feature being configured tobe read by a code sensor of the auto injector for moving a plunger rodof the auto injector to a first plunger rod position based on thecartridge code feature, the first plunger rod position being selected toexpel air from the cartridge.
 31. The cartridge assembly according toclaim 30, wherein the cartridge comprises a cartridge compartmentcontaining the medicament, a cartridge outlet, and a first stoppermovable inside the cartridge compartment towards the cartridge outlet,wherein the cartridge code feature is indicative of a position of thefirst stopper wherein air in the cartridge compartment is reduced. 32.The cartridge assembly according to claim 30, wherein the cartridgecompartment has a first cartridge subcompartment containing a firstmedicament component of the medicament and a second cartridgesubcompartment containing a second medicament component of themedicament, wherein the first medicament component is a fluid and thesecond medicament component is a lyophilized medicament.
 33. A systemcomprising a cartridge assembly and an auto injector, the cartridgeassembly comprising a cartridge and a cartridge code feature, thecartridge containing a medicament, the auto injector comprising: ahousing; a cartridge receiver configured to receive the cartridgeassembly; a code sensor configured to read the cartridge code feature; adrive module coupled to move a plunger rod; and a processing unitcoupled to the code sensor and the drive module; wherein the processingunit is configured to: receive from the code sensor a code signalindicative of the cartridge code feature; and control the drive moduleto move the plunger rod to a first plunger rod position, the firstplunger rod position being based on the code signal, and the firstplunger rod position being selected to expel air from the cartridge. 34.The system according to claim 33, wherein the processing unit is furtherconfigured to: receive a trigger event; and control the drive module tomove the plunger rod to a second plunger rod position followingreception of the trigger event.
 35. A method for operating an autoinjector comprising a plunger rod, the method comprising: receiving acartridge assembly comprising a cartridge and a cartridge code feature,the cartridge containing a medicament; reading the cartridge codefeature; and moving the plunger rod to a first plunger rod position, thefirst plunger rod position being based on the cartridge code feature,and the first plunger rod position being selected to expel air from thecartridge.
 36. The method according to claim 35 further comprising:receiving a trigger event; and moving the plunger rod to a secondplunger rod position following reception of the trigger event.
 37. Themethod according to claim 35, wherein the plunger rod is moved to thefirst plunger rod position with a first plunger rod speed based on thecode signal.